const int ledPins[] = {2, 3, 4, 5}; // LED 1 to LED 4
const int buttonPin = 6;

int patternIndex = 0;
int phaseIndex = 0;
unsigned long lastUpdate = 0;
const unsigned long interval = 500; // 1 second

bool lastButtonState = LOW;
unsigned long lastDebounceTime = 0;
const unsigned long debounceDelay = 50;

// Patterns: each pattern has multiple phases, each phase is a 4-element LED state
const bool patterns[][5][4] = {
  { {1, 1, 1, 1}, {0, 0, 0, 0} },                         // Pattern 1
  { {1, 0, 1, 0}, {0, 1, 0, 1} },                         // Pattern 2
  { {1, 0, 0, 0}, {0, 1, 0, 0}, {0, 0, 1, 0}, {0, 0, 0, 1} }, // Pattern 3
  { {1, 1, 0, 0}, {0, 0, 1, 1} },                         // Pattern 4
  { {1, 0, 0, 1}, {0, 1, 1, 0} }                          // Pattern 5
};

const int patternLengths[] = {2, 2, 4, 2, 2}; // Number of phases per pattern

void setup() {
  for (int i = 0; i < 4; i++) {
    pinMode(ledPins[i], OUTPUT);
  }
  pinMode(buttonPin, INPUT_PULLUP); // Button active LOW
}

void loop() {
  unsigned long currentTime = millis();

  // Handle LED phase update
  if (currentTime - lastUpdate >= interval) {
    lastUpdate = currentTime;

    // Show current phase
    for (int i = 0; i < 4; i++) {
      digitalWrite(ledPins[i], patterns[patternIndex][phaseIndex][i] ? HIGH : LOW);
    }

    // Move to next phase
    phaseIndex++;
    if (phaseIndex >= patternLengths[patternIndex]) {
      phaseIndex = 0;
    }
  }

  // Handle button press to change pattern
  bool reading = !digitalRead(buttonPin); // Invert for pull-up logic

  if (reading != lastButtonState) {
    lastDebounceTime = currentTime;
  }

  if ((currentTime - lastDebounceTime) > debounceDelay) {
    if (reading == HIGH) {
      patternIndex = (patternIndex + 1) % 5;
      phaseIndex = 0; // Reset phase when switching pattern
    }
  }

  lastButtonState = reading;
}